DQ-Router

The DQ-Router is designed for use with the DQ801 DirectQAM™ IP to QAM Modulator. The DQ-Router functions as a combination of Gigabit Ethernet switch, firewall and Quality-of-Service (QoS) router. The DQ-Router is designed to separate the content data and management data to and from the DQ801.

A block diagram is shown below:

DQ-Router Block Diagram

 

Detailed description

The DQ801 is visible from both the Management port and the Content port. However, both ports have different functions and will therefore pass different types of traffic to the DQ801. Likewise, data from the DQ801 to the outside world is examined and only output on the appropriate port.

On the receive side, a QoS block makes sure that incoming traffic on the Content port always takes precedence over data coming in on the Management port. Incoming data from the Management port is buffered until there is some idle time on the DQ801 transmit side. If this buffer overruns, any further incoming packets are discarded until there is enough room in the buffer again.

Both ports see the DQ801 as being on the same IP address and with the same MAC address. This makes the DQ-Router completely transparent to the Content and Management sides of the controlling networks. The drawback is that Content and Management terminals must be on physically separated networks.

The main advantages for this setup are that the DQ-Router requires no configuration or management, and it forces the end user to provide a separate content data network with less management traffic “pollution”, thereby reducing packet jitter.

DQ-Router PCB Topview

Other possibilities

The flexibility of the DQ-Router platform allows for a number of alternative configuration options. An example of this is shown in the diagrams below.
By loading one or more DQ-Router boards with a slightly modified firmware, you could be able to connect two, or even three DirectQAM™ units to a single pair of management and content cables.
DQ-Router - Alternative Configuration option 1
Configuration Option using DQ-Router boards to connect 2 DirectQAM™ units to 1 pair of management and data cables.

DQ-Router - Alternative Configuration option 2
Configuration Option using DQ-Router boards to connect 3 DirectQAM™ units to 1 pair of management and data cables.
(note that the DirectQAM™ units cannot be used to their full bandwidth in this configuration due to the limitation to 1 GBps.)

 

Download the detailed product description.

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